Process of purifying iron.



rosiirn msxo, or BUFFALO,

NEW YORK, Assrenon or oNE-HALF m E. n. monsnson, or

STOVALL, NORTH CAROLINA.

PROCESS OF PURIFYING IRON.

Specification of Letters Patent.

Patented Oct. 15, 1907.

Application filed January 5,1907. Serial No. 350,941.

To all whom 'it may concern: 1

Be it known that I, Josnrn MISKO, of Buffalo, county of Erie, State ofNew York, have invented a new and useful Process of Purifying Iron.

The object of my invention is ultimately to purify molten iron or steel,especially by eliminating'the gases contained therein and to get rid offurther impurities,

- thereby rendering the product stronger and more homogeneous.

It is well known that molten iron and especially steel contain a greatmany mechanically occluded or inter- 4 5 character.

molecular dissolved and reactionary gases, such as oxygen, nitrogen,hydrogen, carbonic oxid, carbon dioxid, and other gases. These gasesmean discontinuity of mass and lack of strength. To eliminate theseimpurities, I make use of the metal calcium. Since the metal calcium isvery expensive, I make use of it in a compound formv The compound ofcourse has to be of a character that will melt easily and decompose inmolten iron or steel to liberate the metallic 'calcium'ior action.Calcium carbid is the best compound that will serve the purpose, but themelting point of this carbid is so very l high that it has to be firstlowered. have found that calcium carbid will alloy with iron readily,and form what may be termed ferro-calcium-carbid, the melting i point ofwhich is very much lower, according to the i amount of iron containedtherein. It furthermore remains liquid for a much longer time, a veryessential feature in the process.

To purify iron or steel, I first meltit and add to it molten ferrocalcium-c arbid containing about 90% of iron, about 6% of calcium andabout 4% of carbon. The reaction is almost instantaneous. The metallicc'alcium has a much greater affinity for the impurities and gasescontained in the iron than it has for either the carbon in the carbid orthe ,iron with which itis alloyed. And therefore the carbid decomposesinstantly and the nascent atoms of the metallic calcium combine with thesulfur and burn into calcium sulfid; with the phosphorone into calciumphosphide, with the gases into oxids, nitrids, fiuorids and othercombinations. Carbonic oxid and carbon dioxid is decomposed by it, aswell as the slagcontained in the metal, and the oxygen in each casecombines with the calcium to form salts of various 1 All of these saltscome to the surface in the term of slag and are easily eliminated andthereby the 10% and lhave found 80 or 90% 'nickel or molybdenum etc.

purification desired is effected. It is not necessary in all cases tomelt the ferro calcium-carbid as it can be readily thrown into an openhearth furnace containing moltensteel, or into a Bessemer converter, andalso into a cupola furnace where cast iron is being melted.

In making ferro-calciumc'arbid, the iron may either be added in theproportion desired at the time of adding the charge for making calciumcarbid to the electric furnace or after the calcium carbid is formed inthe furnace, the ironmay be added. Of course purematerials should beused in forming ferro-calcium-carbid' In regard to the proportion ofiron which is to be added to the carbon and lime, this is not materialprovided enough iron is added to reduce the melting point of theferro-calcium-carbid to a point at which it will melt in connection withthe iron which is to be purified. The iron should, however, in anyevent, be in excess oi of iron to be advan-. tageous; charge otheralloying compounds such as ierro-titanium,ferro-chromium,term-manganese, term-vanadium, These are preferably to beadded in the desired proportions after the purification byferro-calciumcarbid,.but in some cases they may be alloyed or compoundedwith ferro-calcium-carbid and simultaneously added. It will be foundthat the proportionate amount of these rarer metals to be added willbeless after the primary purification by ferro-calciumcarbid than thoughthe iron had not been originally so 7 5 purified. Of these rarer metalsI prefer titanium and for some purposes cobalt may be used but in allcases according to my invention ferro-calcium-carbid must be used forthe purification of the iron so as to obtain the most beneficial resultsfrom the addition of the rarer metals.

What lclaim as my invention and desire to secure Letters Patent is z--The process of purifying iron, which consists in adding theretoferro-calcium-carbid and fusing the same therein,

substantially as described. I

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

\ JOSEPH MISKO.

Witnesses: I v CHAS. E. Rnnn, Mrs. C. E. Rnnn.

I also propose to add to the purified iron 65 i

